Cationization of cellulose by using N‐oxiranylmethyl‐N‐methylmorpholinium chloride and 2‐oxiranylpyridine as etherification agents

Cationization of cellulose under aqueous alkaline conditions was studied. Two new epoxy reagents, N-oxiranylmethyl-N-methylmorpolinitim chloride and 2-oxiranylpyridine, were used for preparation of cationic cellulose ethers. Using the first agent, cationic ethers were obtained in one step, whereas the latter one yielded a reactive intermediate used as a precursor for two different cationizations. Etherification with the commonly used 2,3-epoxypropyltrimethylammonium chloride was also performed and used as a reference reaction. By changing water content in the reaction mixture two groups cellulose ethers with different degrees of cationization were prepared. As expected, reducing the water content resulted in a higher degree of etherification and hence a more pronounced cationic character of the obtained ethers. Characterization by FTIR, elemental- and gravimetric analysis confirmed the formation of the desired ethers. Their ability to interact with water and adsorb the acid dye, methyl orange, was also studied, confirming further introduction of the cationic substituents and revealing different reactivities of the used epoxy reagents. From characterization, it could be concluded that N-oxiranylmethyl-N-methylmorpholinium chloride exhibits higher reactivity toward cellulose than both the reference compounds and 2-oxiranylpyridine. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 114: 1449-1456, 2009